Press for bending wood.



No. 723,573. PATENTED MAR. 24, 1903.

F. H. BANGROFT. PRESS FOR BENDING WOOD.

APPLICATION nun NOV. 1, 1399. no MODEL. a SHEETS-SHEET 1.

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No. 723,573. PATENTBD MAR. 24, 1903.

F. H. BANGROPT.-. v PRESS FOR BENDING WOOD.

APPLICATION FILED HOV. 1, 1899.

NO MODEL. 4 3 SHEETS SHEETZZ.

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0/ I I/I/I/jll/Il/l'l/Ill/II/l/II/ IIII/IIIII/I No. 723,573. PATENTED MAR. 24, 1903.

F. H. BANGROFT. PRESS FOR. BENDING WOOD.

APPLIOATION FILED NOV. 1, 1899.

N0 MODEL 3 SHEETS--SHEET 3x FIE-.5.

UNITED STATES ATENT ()FFICE.

FRANK H. BANOROFT, OF GARDNER, MASSACHUSETTS, ASSIGNOR OF ONE- HALF TO HENRY M. RICH, OF GARDNER, MASSACHUSETTS.

PRESS FOR BIENDIN'G wooo.

SPECIFICATION forming part 01 Letters Patent N 0. 723,573, dated March 24, 1903.

Application filed November 1, 1899- Serial No. 735,452. (No model.)

To all whom it may concern.-

Be it known that I, FRANK H. BANOROFT, a citizen of the United States, residing at Gardnor, in the county of Worcester and Commonwealth of Massachusetts, have invented new and useful Improvements in Presses for' Bending Wood, of which the following is a specification, accompanied by drawings forming a part of the same, in which- Figure 1 represents a front view of a press for bending wood embodying my invention. Fig. 2 is an end view of the same. Fig. 3 represents in sectional view the jointed steampipe connection between the hollow forms of the press. Fig. 4 is a'top view of the swivelbearing between the hollow forms and the upright posts on which the hollow forms slide. Fig. 5 is a sectional view of the same on line 5 5, Fig. 4:. Fig. 6 is a top view of a modified form of the swivel-bearing between the hollow forms and the upright posts on which the forms slide and showing means for attaching the forms to the posts; and Fig. 7 is an end view of the same shown partly in section on line 7 7, Fig. 6.

Similar letters refer to similar parts in the difierent figures,

My invention relates to a press having fixed and reciprocating members whose opposing 3o surfaces are curved or so shaped as to bend pieces of wood placed between them; and it. has for its object to increase the efficiency of machines of this class; and it consists in the construction and arrangement of parts, as

hereinafter described, and set forth in the annexed claims.

Referring to the drawings, A denotes the base of the machine, supporting an actuating mechanism which in the present instance consists of a hydraulic cylinder having a plunger or piston B.

Mounted upon the base A are parallel upright posts A, united at their top by a fixed cross-head O, constituting the upper form and 5 consisting of a hollow shell having its under side 0 presenting a curved surface forming a fixed pressing-surface, which is provided in its central section with semicircular depressions G which extend transversely across the central portion of the pressing-surface O.

Beneath the cross-head O is a similarlyshaped hollow form D, having ears D inclosing the posts A and capable of sliding thereon. The form D has a concave upper surface D forming the opposing pressing-surface to the under surface 0 of the cross-head O, and it has also a convex under surface D which rests upon the upper surface of the next lower hollow form E. The hollow form E has a slightly-concave upper surface E, forming a support for the convex surface D of the form D, which is capable of a slight rocking motion thereon, as hereinafter described. The lower surface E of the hollow form E is slightly convex and is provided with trans verse semicircular depressions E The hollow form E is also provided with ears E, which inclose the posts A and permit a vertical sliding motion thereon. Below the hollow form E is a similarly-shaped hollow form F, having l ears F, inclosing the posts A and capable of sliding thereon, and having wing-pieces F F, attached by bolts F to the front and rear edges of the form F, said wing-pieces having transverse semicircular depressions F on their upper surfaces, which are slightly raised above the concave upper surface F of the frame F. Beneath the form F is a hollow form G, having a concave upper surface G, corresponding in curvature to the opposing convex under surface F of the form F. To the front and rear edges of the form G are attached wing-pieces G by means of bolts G having their upper surfaces G coincident with the upper surface G of the form G. The form G is provided with ears G inclosing the posts A and capable of sliding thereon.

The form G is attached to the plunger B, by which it is given a vertical sliding motion on the posts A. The fixed cross-head O is provided with studs H, upon which are suspended links H, which inclose similar studs H on the form D, by which the form D is suspended when at its lowest position from the cross-head 0. Similarly the form E is suspended from the form D by links I, hanging upon the studs H and inclosing the studs 1, and the form F is suspended by links J, hanging upon the studsI and inclosing the studs J. In order to obtain a uniform hearing upon each of the suspension-links, I suspend eaoh form bya pair of links at one end head C in Fig. 3.

and bya single link at its opposite end, thereby supporting each of the suspended forms at three points. Steam is admitted to one end of the' hollow crosshead O by a steampipe a, which enters the hollow cross-head C, with the inner end of the pipe 1) extending nearly to the opposite end of the cross-head, as shown in the sectional view of the cross- The end' of the cross-head at which the steam is admitted is connected with the corresponding end of the next lower form D by a pipe connection 0, comprising the swivel pipe-joints d, e, and f, (shown in sectional View in Fig. 3,) each of said joints being capable of rotating around the inclosed pipe, thereby permitting the rising-and-falling motion of the forms on the posts A and preserving the steam connection between them. Similarly the forms D, E, F, and G are connected by swivel pipe connections g hi, and exhaust-steam is taken from the form G through the pipe 9'. Each of the steam-pipes th ough which steam enters the form is carriedto the opposite end of the form, as already described, so that in each form the steam is taken in at one end of the form and delivered from the pipe at the opposite end of the form, so that the steam is obliged to traverse the entire length of the forms in passing from the admission to the exhaust pipes, as shown in Fig. 3.

Each of the ears D, E, and F upon the movable forms D, E, and F are provided with the elongated holes K to receive the posts A, and between the posts and the ends of the forms is a bearing-block'L, fitting one side of the post and pivotally connected at its opposite side with the end of the form' by means of a pin L, and the block L is provided with oppositelybeveled sides L by which the form is capable of aslight rocking motion. Each of the ears is provided with a stud M, adapted to be inclosed by links N when the forms are brought together with the pieces of wood compressed between them, thereby locking each pair of pressing members together,.so that the bent pieces of wood between them may be clamped in position.

In the machine illustrated in the accompanying drawings the pressing-surfaces of the cross-head C and form D are adapted for bending the short circular pieces of wood employed in chair manufacture and known as arms. The pressing-surfaces between the forms E and F are adapted for bending the posts, and the pressingsurfaces of the forms F and G are adapted for bending the rockers, the special adaptation for the different kinds of work consisting, however, in the area and conformation of the pressingsurfaces, the semicircular depressions on the pressing-surfaces of the forms C, D, E, and F adapting them for such pieces of wood as are circular in cross-section.

Between each of the pressing-surfaces I place a removable metallic piece, corresponding in cross-section to the piece of wood to be bent, for the purpose of limiting the movement of the pressing members and preventing the crushing of the wood inserted between them. I have shown one of these pieces in Fig. 1 as placed between the forms E and F and consisting of a metal bar 0, corresponding in cross-section to one of the posts to be bent and curved to correspond to the curvature of the posts as they are bent by the compression of the forms E and F. The bar 0 is provided with ears at each end, one of which is shown at 0, Fig. 1,which overlap the sides of the form F and hold the bar from longitudinal movement.

In the operation of my machine in bending chair-stock, pieces to form arms are placed between the cross-head O and the form D, pieces to form posts are placed between the forms E and F, and pieces to form rockers are placed between the forms F and G, all of the forms having been heated by the introduction of steam. The form G is then raised by the hydraulic cylinder and plunger B, lifting all the movable forms toward the crosshead G and compressing the interposed pieces of wood, which are bent-into the desired curvature by the curved pressing-surfaces of the forms. The pressing-surfaces are then locked together by the links until the wood is dried by the heated forms. Each pair of pressingsurfaces are then successively unclamped by releasing thelr locking links and refilled, thereby allowing thepieces inserted between each pair of forms to be withdrawn and others substituted while the remaining forms are still clamped together. As the pieces interposed between the pressing-surfaces are sometimes thicker at one end than at the other-as in the case of chair-posts, for example-it is necessary to provide'for a. slight rocking motion of the movable forms, and this is permitted by means of the. swiveled bearingblocks L, thereby producing a uniform pressure of the wood upon the opposite sides of the posts A by causing the form D to be supported by and to rock upon the form E.

One of the swiveled pipe connections be tween the cross-head and the movable forms is shown in Fig. 3 and is provided with duplicate rotating joints (1, e, and f. The joint d consists of a central pipe to, one end of which is screwed into the end of the cross-head O, and the opposite end enters and is capable of turning in the elbowl and is held by a collar m, screwed upon the end of the pipe 75.

Screwed upon the end of the elbow l and upon a collar n is a coupling-sleeve o, inclosvertical movement of the forms on the posts A.

In Figs. 6 and 7 I have shown what I consider a preferable method of forming the bearings of the several forms on the upright posts and also means for attaching the forms to the upright posts in order to hold each pair of pressing members together with the bent pieces of wood clamped between them in lieu of the links N and studs M. As shown in Figs. 6 and 7, the post A is inclosed between two bearing-blocks O O,which are placed on opposite sides of the post A and are adapted to be pressed against the post by means of a binding-screw held in the ears D with its end drawing against the outer side 0 of the bearing-block O, with the outer side of the bearing-block O in contact with the inner wall R of the ear, so that by screwing the screw P against the block 0 will cause the post A to be clamped between the blocks 0 and 0, thereby holding the form from moving on the post. The bearing-blocks O and O are rectangular in outline, and the opposite outer sides 0 and O are beveled or tapered from the center toward each end to allow a slight rocking motion of the form on the post. Each of the bearing-blocks is held in position bya stud S, held in the end of the form and entering semicircular recesses T T- in the opposite sides of the blocks 0 and O. The semicircular recesses T T extend entirely across the opposing sides of the blocks 0 and O and are in alinement with a hole U in the front of the ear D in order to allow the stud S to be inserted after the bearing-blocks are in position.

I deem the employment of a pair of bear ing-blocks and a binding-screw a preferable method of holding the pairs of forms in position with the bent pieces of wood clamped between them instead of the studs M and links N, as the use of the links and studs does not allow for any considerable variation in the thickness of the wood to be bent.

What I claim as my invention, and desire to secure by Letters Patent, is

1. In a press for bending wood, comprising a multiplicity of pressing members, the combination of vertical posts, reciprocating forms provided with ears inclosing said posts and blocks bearing against said posts and pivoted to said forms, whereby said forms are capable of a rocking motion, substantially as described.

2. In a press for bending wood comprising a series of pressing members, the combination with pressing members at each end of said series incapable of rocking, of a pair of intervening pressing members having their opposing surfaces in contact and capable of a rocking motion, substantially as described.

3. In a press for bending wood, the combination with upright posts of pressing members capable of sliding on said posts and means for rigidly attaching said pressing members to said posts so as to hold the upper series of staves in a clamped position while the lower series are released, substantially as described.

4. In a press for bending wood, the combination of upright posts, pressing members capable of sliding on said posts and provided with ears inclosing said posts, bearing-blocks held in said ears and inclosing said posts, a pivotal stud by which said blocks are held in position and a binding-screw for clam ping the blocks on the post, substantially as described.

5. In a press for bending wood, comprising a multiplicity of pressing members, the combination of two pairs of pressing members having the opposingsurfaces of the adjacent members of each pair in contact and capable of rocking motion, one on the other, and means for crowding said pressing members together,

6: In a press for bending wood, the combination of a pair of pressing members and a metal stop interposed between the opposing surfaces of said members, said stop correspondin g in curvature and cross-section to the wood when bent, substantially as described.

In testimony whereof I have signed my name to this specification, in presence of two subscribing witnesses, this 27th day of Octo ber, 1899.

FRANK H. BANOROFT.

Witnesses:

J ENNIE A. WALLACE, G. H. Tower. 

